Dual-mode satellite/terrestrial mobile communication unit

ABSTRACT

The present invention seeks to provide a dual mode mobile satellite communication unit, which requires low communication cost and very little battery power, does not require always carrying a large unit frame and does not always provide great weight burden on the user. A terrestrial communication portable unit is detachably mounted in the mobile satellite communication unit. The mobile satellite communication unit as base unit does not include a key operating section, a display section and a speech transducer section having a microphone and a loudspeaker, and utilizes those mechanically assembled on the portable unit side for keying and other operations. 
     In an interlocked relation to the removal of the portable unit, the stand-by state of the base unit is turned off. It is thus possible to avoid wasteful battery power consumption on the base unit side. Using a hollow cylindrical antenna, the inner cylindrical space thereof is used as a battery insertion space, thus dispensing with an independent battery mounting space. Very great space saving is thus attainable particularly in a mobile satellite communication unit, which requires high power and large size battery power supply.

FIELD OF THE INVENTION

This invention relates to commonly termed mobile satellite communicationunits utilizing satellites orbiting around the earth as networkswitching nodes and, more particularly, to dual mode mobile satellitecommunication units, which can be used as mobile terrestrialcommunication unit for cellular or PHS communication systems utilizingterrestrial radio stations as well as the mobile satellite communicationunit.

PRIOR ART

As an example of mobile satellite communication system, an iridium plancommunication system of Motoroller Inc. in U.S.A. is well known in theart. FIG. 11 depicts the iridium plan communication system, which isshown in, for instance, Japanese Laid-Open Patent Publication No.6-181456. A constellation 100 consists of, for instance, 66 satellites200 moving along relatively low level orbits around the earth (notshown). Line-of-sight communication may be made from given points on theearth's surface with an obstructed view to one or more satellites. Theconstellation and the satellites which are moving along relatively lowlevel orbits, are always moving relative to the earth. For example, asatellite moving along an orbit 765 km apart from the earth, is movingat a speed of about 25,000 km relative to an earth's surface point. Thissatellite is in the visual field of the earth surface's point for aperiod of at most about 9 minutes.

At every area or country on the earth's surface, a number of switchingoffices (SO) 101 are provided for data communication with satellitesamong adjacent ones of them via r-f trunking communication links 102.The satellites are also doing data communication with one another viatrunking communication links.

A switching office 101 in any area on the earth can controlcommunication (or calls) sent out to given points via the constellation100. Each switching office 101 is coupled to a usual phone switchingnetwork (PSTN) 103 via a number of PSTN lines, and also can receivecalls sent out from PSTN lines to mobile satellite communication linesubscribers 104. The PSTN lines 103 can send out calls transmitted fromthe mobile satellite communication line subscribers 104.

As many as several million mobile satellite communication units MU arecoupled to each mobile satellite communication line. The mobilesatellite communication units MU can do communication at any place in anearth area covered by the mobile satellite communication network.

FIG. 12 shows a personal handyphone system (PHS) mobile communicationsystem pertaining to the present invention (which is shown in, forinstance, Japanese Laid-Open Patent Publication No. 7-187866). Thesystem comprises a PHS control center 140 for storing position data, aplurality of relay stations 132 each wired via a digital switchingoffice 131 and a common line signal network 130 to the PHS controlcenter 140, and a plurality of base stations 120 wired to each of therelay stations 132. The relay stations 132 produces position data on thebasis of position registration requests sent out from the base stations120.

In the position registration in such a system, a PHS unit 110 receivingposition data notified from the pertinent base station 120 checks thedata. When the data is different from position registration data storedin it, the PHS unit 110 sends out a position registration signal to thebase station 120 in the radio zone (or position registration area 134)in which the user is present. The position registration signal isrelayed by the relay station 132 and arrives at the PHS control center140 in a converted form necessary for switching. The present positiondata of the PHS unit 110 is thus stored in the PHS control center 140.The above operation is executed whenever the position registration area134 is changed by movement of the PHS unit 110.

When the number of the PHS unit 110 is dialed from a general subscriberphone, the transmission side digital switching office 131 interrogatesthe PHS control center 140 via the common line signal network 130 aboutthe position registration area 134 in which the PHS unit 110 of thedialed number is present, i.e., about position registration datanecessary for switching. On the basis of this position registrationdata, tracing connection is made, and the base stations 120 in thepertinent position registration area 134 make a general terrestrialradio wave calling.

When a PHS unit 110 dials a general subscriber phone number, thesubscriber certification data number of the PHS unit 110 is transmitteddtogether with the phone number via the base station 120 to the relaystation 132. The relay station 132 identifies the PHS unit 110 andconfirms that the transmitter is a subscriber. Then, a line concerningthe general subscriber phone is connected.

As is seen from the above description of the prior art, the mobilesatellite communication unit is capable of making communication at anyplace on the earth under the mobile satellite communication network. Aproblem, however, is posed that high power is necessary forelectromagnetic waves to reach the constellation which is utilized asnetwork switching nodes, because the constellation is disposed alongorbits spaced apart by 765 km from the earth.

In the mobile satellite communication unit, therefore, not only thetransmitting circuit but also the battery power supply are inevitablylarge in size. Consequently, the unit requires high communication costand much battery consumption, and also its frame has a large size. Thatis, a large size frame should always be carried as the mobile satellitecommunication unit. Unlike the case of carrying a recent small sizeunit, this is a great weight burden on the user.

The mobile terrestrial communication unit for the PHS or cellularsystem, on the other hand, in spite of its restriction that it permitscommunication in only prescribed areas, is for communication bytransmitting and receiving data to and from a base station close to it.Thus, unlike the mobile satellite communication unit, the transmittingcircuit and the battery power supply of the unit are small in size, andalso the unit requires low communication cost and little batteryconsumption.

An advantageous mobile satellite communication unit is a duel mode one,which can provide the functions of both the units, i.e., those of themobile satellite communication unit and the mobile terrestrialcommunication unit. Such a dual mode unit, however, is large in size andheavy in weight. Nevertheless, it should always be carried even by theuser who uses the sole mobile terrestrial communication unit function(i.e., utilizes the sole cellular system of PHS services). This is agreat weight burden on the user compared to the case of carrying therecent small size cellular system or PHS unit.

A further problem is that for mobile satellite communication whichcovers the whole globe, it is necessary to use different dual mode unitsin correspondence to different mobile terrestrial communication unitsdepending on areas where the units are sold and used. To solve thisproblem, units in which a terrestrial communication function cartridge(including a ratio section, communication system control programs and adata memory) can be detachably inserted, have been investigated. Suchunits, however, again dictate carrying a large unit frame.

SUMMARY OF THE INVENTION

The present invention, in view of the above technical problems, has anobject of providing a dual mode mobile satellite communication unit,which requires as low communication cost and as little battery power aspossible, neither requires always carrying a large size unit frame nornecessitates user's great weight burden.

Another object of the present invention is to provide a mobile satellitecommunication unit, which can be readily carried and permits volumereduction.

The above and other objects of the present invention will become clearfrom the following description of the present invention.

In solving the problems described before, it is a preamble of thepresent invention that a dual mode mobile satellite communication unit,which provides the mobile terrestrial communication unit function inaddition to the function of a mobile satellite communication unitutilizing satellites orbiting around the earth.

The dual mode mobile satellite communication unit features that:

it comprises a base unit not including at least a key operating section,a display section and a speech transducer section having a microphoneand a loudspeaker and capable of providing the mobile satellitecommunication unit function; and

a terrestrial communication portable unit including a key operatingsection, a display section and a speech transducer section having amicrophone and a loudspeaker and providing a pertinent mobileterrestrial communication unit function;

wherein recesses and projections are provided as mechanical copulters onthe two units for mechanically coupling the two units to each other, andelectric connectors are provided on the two units for electricallyconnecting the key operating section, the display section and the speechtransducer section having the microphone and the loudspeaker on the sideof the terrestrial communication portable unit and a mobile satellitecommunication unit function section on the side of the base unit to oneanother when the two units are mechanically coupled to one another.

With this construction, independent battery power supplies may beprovided in the terrestrial communication portable unit and in the baseunit providing the mobile satellite communication unit function, and interrestrial service areas the small size terrestrial communicationportable unit alone may be carried for use.

In this case, in an interlocked relation to the dismounting of theterrestrial communication portable unit, a stand-by state of the baseunit is switched off, and it is possible to avoid wasteful battery powerconsumption on the side of the base unit.

When it is forecast that the user carrying the portable unit gets out ofa terrestrial service area, the portable unit is mechanically coupled tothe base unit, whereby the key operating section, the display sectionand the speech transducer section on the side of the portable unit andthe mobile satellite communication unit function section on the side ofthe base unit are electrically connected to one another. In this state,the unit can be used at any locality on the earth as the mobilesatellite communication unit by utilizing the key operating section andthe display section of the portable unit.

The provision of the key operating section and the speech transducersection on the side of the terrestrial communication portable unit,makes it possible, in the case where a phone number memory for calltransmission is provided in the portable unit for satellitecommunication, to make common use of functions (such as call tonetransmission) provided in the portable unit and also make common use ofa phone book registered in an internal memory. It is thus not necessaryto register the phone book independently on the sides of the two units.

In a preferred form of the present invention, a single electricconnector is provided for making the above electric connection, and aplural mechanical couplers capable of being held spaced apart bydifferent distances are provided for the mechanical coupling of the twounits. With this construction, a plurality of portable units havingdifferent shapes (i.e., coupling widths) can be selectively mounted solong as their electric connectors are at a regular position ofconnection. It is thus possible to select desired portable units, suchas PHS and cellular system ones. Also, portable units of differentcommunication systems can be mounted in different countries visited inbusiness trips or the like.

In another preferred form of the present invention, a rail-likemechanical coupler movable in a predetermined axial direction isprovided for the mechanical coupling, and an electric connector for theelectric connection is disposed at the end of movement axial directionof the mechanical coupler and in a fixed plane containing the path ofmovement axis of the mechanical coupler. With this construction, aportable unit having any shape and having a rail-like recess formed inthe rear surface can be mounted so long as its electric connector is ata regular position of connection. In addition, since the electricconnector is located in the fixed plane containing the path of movementof the mechanical coupler, reliable electric connection can be ensured.Moreover, shocks generated when dismounting the portable unit isreceived in the above movement path plane, thus eliminating thepossibility of rupture of the electric connector.

The above dual mode mobile satellite communication unit suitably has thefollowing circuit construction.

The present invention features that the base unit which does not includeat least the key operating section, the display section and the speechtransducer section having the microphone and the loudspeaker and iscapable of providing the mobile satellite communication unit function,includes a signal transceiver section for transmitting and receivingconverted wave of transmission and reception signals, preferably PCMdata, to and from the separate terrestrial communication unit.

Particularly, the present invention features, in the above combinationof mobile satellite communication base unit and terrestrialcommunication portable unit:

a mobile satellite communication unit as a base unit not including atleast a key operating section, a display sections and a speechtransducer section having a microphone and a loudspeaker, capable ofproviding the mobile satellite communication unit function and includinga first converted wave transceiver section for transmitting andreceiving converted waves of transmission and reception signals to andfrom a signal transceiver section of the separate mobile terrestrialcommunication unit; and

a terrestrial communication unit as a portable unit including a keyoperating section, a display section and a speech transducer sectionhaving a microphone and a loudspeaker, providing a pertinent terrestrialcommunication unit function and including the second converted wavetransceiver section as noted above, for transmitting and receivingconverted waves of transmission and reception signals to and from thesignal transceiver section of the mobile satellite communication baseunit;

wherein the portable unit is used for terrestrial communication, and themobile satellite communication unit can be used as base unit fortransmission and reception via the first and second converted wavetransceiver sections by utilizing the key operating section and thespeech transducer section having the microphone and the loudspeaker ofthe portable unit during mobile satellite communication.

For short distance transmission and reception, the first and secondconverted wave transceiver sections suitably use infrared transducers orr-f modulator/demodulators, which can transmit infrared rays or weakelectromagnetic waves. As an alternative, it is possible to permit wiredtransmission and reception in lieu of the radio transmission andreception.

With this construction, in terrestrial service areas the user canreceive terrestrial services by carrying the small size terrestrialcommunication portable unit alone.

When the terrestrial and satellite communication units are disposed innearby localities in a terrestrial service area and in a distance rangepermitting transmission of infrared rays and weak electromagnetic waves,a call received by the mobile satellite communication unit for aniridium plan communication system line, is transmitted via the first andsecond converted wave transceiver sections to the speech transducersection on the side of the mobile terrestrial communication portableunit, for doing predetermined transmission and reception by drivingloudspeaker or vibrator.

Suitably, when the user is carrying the small size terrestrialcommunication portable unit alone and moving to increase the distancebetween the two units and gets out of the range permitting transmissionbetween the first and second converted wave transceiver sections, astand-by state of the mobile satellite communication base unit is turnedoff. Suitably, thus, the stand-by state is also turned off in aninterlocked relation to the dismounting of the portable unit. In theseways, it is possible to avoid wasteful battery power consumption on theside of the mobile satellite communication unit.

When it is forecast that the user gets out of a terrestrial servicearea, the terrestrial communication portable unit is electricallycoupled to the mobile satellite communication base unit. By so doing, itis possible to send out a call from the side of the mobile satellitecommunication base unit to satellites by utilizing the key operatingsection and the display section on the side of the terrestrialcommunication portable unit. In this way, it is possible to use the unitat any locality on the earth.

The provision of the key operating section and the speech transducersection on the side of the terrestrial communication portable unit,makes it possible, in the case where a phone number memory for calltransmission is provided in the portable unit for satellitecommunication, to commonly use such functions as call tone transmissionprovided in the portable unit and also commonly use a phone bookregistered in an internal memory. It is thus not necessary to registerthe phone book independently on the sides of the two units.

Since the mobile satellite communication unit does not have any keyoperating section, any display section and any speech transducer sectionhaving a microphone and a loudspeaker, its weight can be correspondinglyreduced. Besides, since this unit can be made integral with the portableunit by electric coupling, the user can carry the portable unit, whichis super-light in weight, in a suit pocket while putting the heavymobile satellite communication unit in a briefcase so long as the useris in an area permitting transmission between the first and secondconverted wave transceiver sections.

According to the present invention, it is possible to selectively usethe terrestrial communication portable unit for short distancecommunication and the mobile satellite communication unit for longdistance communication. The communication cost thus can be logicallyreduced. In addition, since the key operating section and the speechtransducer section are provided only on the terrestrial communicationportable unit side, the weight of the mobile satellite communicationunit can be correspondingly reduced.

According to the present invention, it is possible to selectively mounta plurality of portable units different in the shape and the terrestrialcommunication specifications so long as they have the second convertedwave transceiver. It is thus possible to select desired portable units,such as PHS and cellular system ones. It is also possible to selectdifferent portable units in different countries visited in businesstrips or the like. It is thus possible to obtain electric coupling.

The mobile satellite communication unit has a further problem that itshould have a large battery accommodation space. Since this unitrequires high power so that transmitted waves can reach constellation,the battery used is inevitably large in size, dictating large size andlarge wall thickness of the frame and resulting in a frame, which isvery inconvenient to hold from the human engineering standpoint.

The present invention features, in a commonly termed mobile satellitecommunication unit utilizing satellites orbiting around the earth asnetwork switching nodes, that an antenna section including a microstripplanar antenna at an end is formed such that it has a hollow cylindricalshape and that a battery insertion space is formed in the hollowcylindrical space underneath the microstrip planar antenna.

The antenna section may be capable of elongation and contraction,tilting or rotatable with respect to the unit frame, or it may besecured thereat. The antenna may be mounted in any manner. Suitably,however, the antenna is capable of controlling its angle and also can bepulled out for use because the mobile satellite communication unittransmits and receives weak and highly directive digital signals withrespect to satellites.

The antenna may be the sole microstrip planar antenna, or it may be acomposite antenna obtained by coaxially arranging a microstrip planarantenna and a helical antenna.

The present invention further proposes, as a preferred shape of unitwhich accommodates the above antenna, one constituted by a verticallyelongate frame having an large thickness portion formed on one side, thehollow cylindrical antenna being inserted in the large thicknessportion.

This unit can be used as a single mode mobile satellite communicationunit, which independently permits keying operation and also transmissionand reception. Suitably, however, the unit is used as a dual mode mobilesatellite communication unit, with which keying operation and alsotransmission and reception can be made by utilizing a key operatingsection, a display section and a speech transducer section having amicrophone and a loudspeaker of a separate mobile communication unit forPHS or terrestrial communication.

When applying the present invention to a single mode mobile satellitecommunication unit independently capable of keying operation and alsotransmission and reception, suitably the unit frame has an asymmetrictransversal sectional profile with respect to its front face having akey operating section and a display section, such that a large thicknessportion is formed on one side and a small thickness portion on the otherside behaind the front face, a hollow cylindrical antenna being insertedin the large thickness portion, the inner cylindrical space of theantenna being used as a battery insertion space.

When applying the present invention to a dual mode mobile satellitecommunication unit which utilizes, for keying operation and alsotransmission and reception, a key operating section and a speechtransducer section of a mobile terrestrial communication unit, suitablythe unit frame has a front mounting section for mounting the separatemobile terrestrial communication unit, a large thickness portion isformed on one side behind the mounting section, a hollow cylindricalantenna being inserted in the large thickness portion, the innercylindrical space of the antenna being used as a battery insertionspace.

As described before, suitably such a mobile satellite communication unitdoes not include at least a key operating section, a display section anda speech transducer section having a microphone and a loudspeaker and iscapable of keying operation and also transmission and reception byutilizing a key operating section and a speech transducer section of amobile terrestrial communication unit which is detachably mounted in themounting section.

With the antenna having as hollow cylindrical shape such that the innercylindrical space is used as a battery insertion space, an independentbattery mounting space is unnecessary. It is thus possible to attainvery great space saving particularly in a mobile satellite communicationunit requiring high power and hence a large size battery power supply.

In this case, it is necessary for the portable unit side antenna to holdcommunication sensitivity in all directions around the apex in order tobe able to maintain line quality for variations of the relative positionrelation of satellite unit antenna. Accordingly, the antenna is formed acomposite antenna comprising a microstrip planar antenna and a helicalantenna in coaxial arrangement, thus improving the directivity at lowelevation angle and also the axial ratio thereat.

In the mobile satellite communication unit, a plurality of large sizebatteries are used in series connection. Therefore, the cylindricalantenna inevitably tends to be large in diameter and length.

According to the present invention, this is coped with by thelongitudinally elongate unit frame as noted above, having a largethickness portion formed on one side, the hollow cylindrical antennabeing inserted in the large thickness portion.

When such a frame shape is adopted, it is a problem which side the largethickness portion is formed on.

According to the present invention, the location in which to form thelarge thickness portion for antenna insertion is specified.

The portable unit is held with one hand while doing key operation withthe other hand. The unit is thus held in a space defined by the thumband the index finger. This space is wedge-like, flaring from the root tothe tip of the thumb. In order for the portable unit to be held in sucha space having a wedge-like triangular sectional profile, suitably theunit also has a wedge-like triangular sectional profile. This issuitable from the human engineering standpoint.

Suitably, the unit has a flat front face for providing the key operatingsection, display section and so forth.

According to the present invention, in a unit which is independentlypermitting keying operation and also transmission and reception, theunit frame has an asymmetric transversally sectional profile withrespect to the front face having the key operating section and thedisplay section, such that a large thickness portion is formed on oneside and a small thickness portion on the other side behind the frontface, a hollow cylindrical antenna being inserted in the large thicknessportion.

The mobile satellite communication units can be utilized for shortdistance communication as well as long distance and overseascommunications. When utilized for the short distance communication,however, the communication cost is increased. Suitably, therefore, adual mode mobile satellite communication unit is used in combinationwith a mobile terrestrial communication unit for PHS or cellular systemcommunication.

The present invention is accordingly applied to a unit, which issuitable as a dual mode mobile satellite communication unit utilizing,for key operation and also transmission and reception, a key operatingsection and a speech transducer section of a mobile terrestrialcommunication unit. Specifically, the frame of the unit has a frontmounting section for mounting a separate mobile terrestrialcommunication unit, and a large thickness portion formed on one sidebehind the mounting section, a hollow cylindrical antenna being insertedin the large thickness portion, the inner cylindrical space of theantenna being used as a battery insertion space.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(A) to 1(B) show a dual mode mobile satellite communication unitas a first embodiment of the invention,

FIG. 1(A) showing the unit with an electric connector of a base unit foriridium plan satellite communication held in a buried state, FIG. 1(B)showing the unit with the electric connector in a raised state, FIG.1(C) showing the unit with a portable unit mounted in the base unit;

FIG. 2(A) is a partly broken-apart front view showing the unit shown in

FIG. 1(C), and

FIG. 2(B) is a sectional view taken along line a—a in FIG. 1(C);,omitting the internal construction.

FIG. 3 is a front view showing a dual mode mobile satellitecommunication unit as a different embodiment of the invention;

FIG. 4 is a sectional view taken along line b—b in FIG. 3, not showingthe internal construction of the unit with a portable unit mountedtherein;

FIGS. 5(A) to 5(C) show a dual mode mobile satellite communication unitas a further embodiment of the invention,

FIG. 5(A) being a perspective view showing a base unit for iridium plansatellite communication,

FIG. 5(B) is a partly broken-apart perspective view showing the unitshown in

FIG. 5(A),

FIG. 5(C) being a perspective view showing the unit with a portable unitmounted in the base unit;

FIG. 6(A) is a partly broken-apart front view showing the unit shown inFIG. 5(C), and

FIG. 6(B) is a sectional view taken along line A—A shown in FIG. 6(A);,omitting the internal construction.

FIG. 7 is an exploded perspective view showing a composite antenna shownin FIG. 4;

FIG. 8 is a block diagram showing the internal circuit construction ofportable unit B and base unit A for iridium plan satellite communicationin each of the above embodiments, the two units being coupled togethersuch that signals are mutually transmitted and received via infraredtransducers;

FIG. 9 is a block diagram showing the internal circuit construction ofthe portable unit B and the base unit for iridium plan satellitecommunication in each of the above embodiments, the two units beingcoupled together such that signals are mutually transmitted and receivedvia r-f modulator/demodulators for generating and demodulating lowdirectivity carrier waves;

FIG. 10 is a block diagram showing the internal circuit construction ofthe portable unit B and the base unit A for iridium plan satellitecommunication in each of the above embodiments, the two units beingcoupled together such that signals are mutually transmitted and receivedvia electro-optical transducers and an optical fiber therebetween;

FIG. 11 is a view illustrating an iridium plan mobile satellitecommunication system utilizing a constellation arranged along orbitsaround the earth as network witching nodes;

FIG. 12 is a view illustrating a well-known mobile communication systemfor PHS; and

FIGS. 13(A) to 13(C) show a single mode mobile satellite communicationunit for iridium plan communication, which is different from the aboveembodiments, FIG. 13(A) being a front view, FIG. 13(B) being a top planview, FIG. 13(C) being a sectional view taken along line A—A in FIG.13(A), omitting the internal construction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the invention will now be described by way ofexamples in details with reference to the drawings. It is to beconstrued that unless otherwise specified, the sizes, materials, shapes,dispositions, etc. of components described in connection with theembodiments are not limitative but merely exemplary.

FIGS. 1(A) to 1(C), 2(A) and 2(B) show a dual mode mobile satellitecommunication unit embodying the invention. Designated by A is a baseunit, which excludes at least a key operation section, a display sectionand a speech transducing section having a microphone and a loudspeakerand is necessary for providing the iridium plan communication systemunit function. Designated at B is a portable unit, which is used for PHSor cellular system communication and provides the well-known mobileterrestrial communication unit function.

The base unit A has a vertically elongate, substantially rectangularshape and has a substantially rectangular recess 1 open on the front andextending substantially over the entire vertical dimension of it. Theportable unit B for the PHS or cellular system communication etc. can beaccommodated in the recess 1.

In the recess 1, an electric connector 3 is disposed such that it can beraised from and lowered to the bottom of the recess 1 by verticalsliding of a slide button 2, which is provided in a side wall of theunit A and also serves as a power switch thereof. A pair of innermechanical coupler projections 4 are in right and left side of innerwalls of the unit defining the recess 1. The mechanical couplerprojections 4 are biased by spring forces toward each other.

As shown in FIG. 2(B), each of the mechanical coupler projections 4 hasa substantially right triangular sectional profile with a wedge-likeend. The end of the mechanical coupler projection 4 can be engaged inand secured to an associated mechanical coupling recess 11 on the sideof the portable unit B by a biasing spring 15A disposed inside themechanical coupler projection 4.

The dimension of the mechanical coupler projection 4 up to thewedge-like end thereof is set as desired; for instance, it is set suchas to permit selective mounting of a plurality of PHS and cellularsystem communication units having different shapes (i.e., widths) as theportable unit B.

More specifically, for the portable unit B for PHS and cellular systemcommunication it is a preamble that an electric connector accommodationrecess 12 formed at the bottom and the mechanical coupler recesses 11,which receive the wedge-like ends of the mechanical coupler projections4 provided on the right and left side walls of the base unit A, are at afitted position of connection. With this arrangement, it is possible tomount the portable unit B1 and B2 having different shapes (i.e., widths)as shown in FIG. 2(B).

In this embodiment, the top wall of the recess 1 is partly removed sothat an antenna 13 of the portable unit B can penetrate the top wall ofthe recess 1.

The base unit A has such a transversally sectional profile that its rearsurface has a convex portion on one side, a cylindrical space 5 capableof accommodating a large size battery is formed in the convex portion,and a cylindrical frame 5A of the cylindrical space 5 serves as anantenna.

As described above, the portable unit B of this embodiment, used for PHSand cellular communication, has the electric connector accommodationrecess 12 formed at the bottom and the mechanical coupler recesses 11formed in the right and left side surfaces. The portable unit B also hasthe antenna 13 which extends upright from a left side portion of thetop, a receive-call lamp 19 and a receiver loudspeaker 33 provided on aupper portion of its front face, and a display section 14 provided on alower front face portion for displaying such various information as datatransmitted by key operation or the like.

The front face lower portion further has a power switch, a call switchfor transmitting a call signal, service keys 15 constituted by on-hookswitches and so forth, ten keys 16 provided under the service keys, andfunction keys 17 for volume control, function selection and variousother functions. Together with the function keys 17, a select key 17Fhaving an LED is provided for selecting an iridium plan communicationline. By depressing the select key 17F, the LED is turned on to notifythat the iridium plan communication line has been connected. Designatedat 34 is a microphone.

The select key 17F is electrically controlled such that the LED isturned on when and only when the electric connector 3 on the side of thebase unit A is electrically connected.

In this embodiment, by pushing down a pertinent portable unit B into thebase unit A in a state which the slide button 2 is in the lower setposition so that the electric connector 3 is held buried in the bottom(i.e., in a power “off” state), the wedge-like ends of the pairmechanical coupler projections 4 provided on the right and left innerside walls of the recess 1, are pushed further apart against the springforces biasing them, and then click engaged in the mechanical couplerrecesses 11 provided in the side surfaces of the portable unit B by thespring forces biasing them.

After the engagement, by raising the slide button 2 the electricconnector 3 is raised from its position in the bottom, and enters in andis secured to electric connector accommodation recess 12 formed at thebottom. The two units are thus reliably secured to each other by thethree-point support. In addition, the slide button 2 also serves as apower switch, and power supply to the base unit A is on-off operated inan interlocked relation to the securing of the portable unit B inposition. It is thus possible to avoid wasteful battery powerconsumption.

FIGS. 3 and 4 show a different embodiment of the dual mode mobilesatellite communication unit. Again in this embodiment, a base unit A1has a vertically elongate, substantially rectangular shape and has asubstantially rectangular recess 1 open on the front and extendingsubstantially over the entire vertical dimension of it. In thisembodiment, however, the base unit A1 does not have any top wall of therecess 1A, thus permitting a portable unit B to be slidably insertedfrom above into it. In addition, the base unit A1 has a verticalrail-like ridge 4A extending along the front surface of the rear walldefining the recess 1A and having an inverted trapezoidal transversalsectional profile. An electric connector 3 is raised on the bottom.

The portable unit B for PHS or cellular communication has a verticalrail-like recess 11A for slidably receiving the rail-like ridge 4A. Anelectric connector accommodation recess 12 is recessed at the bottom.

In this embodiment, by slidably inserting the portable unit B down intothe recess 1 with the rail-like ridge 4A engaged in the rail-like recess11A, the electric connector 3 is received in and secured to the electricconnector accomodation recess 12. In the portable unit B for PHS andcellular communication in this embodiment, the electric connectoraccommodation recess 12 recessed at the bottom and the rail-like recess11A which is engaged by the rail-like ridge 4A, are at a fitted portionof connection each other. Thus, as shown in FIG. 4, it is possible toselectively mount the portable units B1 and B2 having different shapes(i.e., widths), and the two units A and B can be reliably secured toeach other by two-surface support, i.e., the bottom surfaces and rearsurfaces.

FIGS. 5(A) to 5(C) and 6 show a further embodiment of the dual modemobile satellite communication unit according to the invention. Thedifference of this embodiment from the previous embodiments will mainlybe described. The base unit A has an infrared transducer 12 a providedon the bottom of the recess 1, and the portable unit B has an infraredtransducer 3 a provided at the bottom. The infrared transducers 12 a and3 a can be brought into a face-to-face relation to each other foreffecting electric connection. The base unit A has a pair of mechanicalcoupler projections 4 provided on the right and left inner wall surfacesof the recess 1 and biased by spring forces toward each other.

The base unit A has a power switch 2 provided on one side wall. Byturning on the power switch 2, a satellite communication stand-by stateis brought about. It is possible to provide, in addition to the powerswitch 2, second switches 11F each in each mechanical coupler recess 4to permit automatic switching between satellite communication stand-bystate and “off” states in an interlocked relation to the mounting of theportable unit B.

An LED 21 provided on the top of the base unit A, permits judgment as towhether the satellite communication state is “stand-by” or “off”, andalso whether a satellite communication call is being transmitted orreceived. The LED 21 indicates the satellite communication “off” stateby emitting red light, indicates the satellite communication stand-bystate by emitting green light, indicates a state of call transmission orreception by emitting flickering green light, and indicates the statethat the battery has been used up by emitting flickering red light.

As described above, the portable unit B for PHS or cellular systemcommunication in this embodiment has the infrared transducer 12 aprovided on the bottom and the mechanical coupler recesses 11 providedon the right and left inner side wall surfaces, and also has thepermissive switches 11F, which are disposed in the mechanical couplerrecesses 11 and permits the use of the iridium plan communication line.When the permissive switches 11F are depressed via the mechanicalcoupler recesses 11 and the power switch 2 is turned on, the displaysection 14 notifies that the iridium plan communication line has beenconnected.

In this embodiment, by forcibly inserting a pertinent portable unit Bdown into the recess 1 of the base unit A with the power switch 2 held“on”, the wedge-like ends of the mechanical coupler projections 4provided on the right and left inner side wall surfaces of the recess 1,are pushed further apart against the spring forces biasing them, andthen click engaged in the mechanical coupler recesses 11 provided on theside of the portable unit B, thus depressing the permissive switches 11Fvia the mechanical coupler recesses 11.

By making the above engagement, the display section 14 notifies that theiridium plan communication line has been connected, and at the same timethe infrared transducers 3 a and 12 a of the two units are brought intoa face-to-face relation to each other to effect electric connection.

The shape of the antenna in the base unit A used satellite communicationin each of the above embodiments will now be described with reference toFIGS. 5(A) to 5(B) and 7.

As shown in FIGS. 1 to 7, specifically FIG. 2(B), the base unit A hassuch a transverse sectional profile that its rear surface has a convexportion formed on one side, i.e., on the right side (that is on the leftside in the front view of the base unit A), of the vertical center. Acylindrical space 5A capable of accommodating a large size battery 45 isformed in the convex portion, and a cylindrical frame 5 of thecylindrical space 5A serves the role of a composite antenna.

The composite antenna 5, as shown in FIG. 7, comprises a microstripplanar antenna and a helical antenna, these antennas being coaxial toeach other. In the figure, designated at 51 is a microstrip planarantenna (hereinafter abbreviated as MSA) of a single-point rear sidepower supply system, at 52 a helical antenna, and at 53 a disc conductorserving to ground the MSA 51 and also supplying power to the helicalantenna 52.

Designated at 51 a is a power supply pin of the MSA, 51 b a batch-likeradiating element of the MSA, 51 c a dielectric base of the MSA, 52 a adielectric post supporting the helical antenna, 52 b linear radiatingelement of the helical antenna, 52 c an insulator for preventing amutual contact of radiating element at the bottom intersection of thehelical antenna. Designated at 52 d is the intersection of radiatingelement at the bottom of the helical antenna 52. The power supply pin 51a is disposed at a position deviated from the diagonal center of thebatch-like radiating element 51 b. A power supply line 51 d which isconnected to the power supply pin 51 a from the back side of the MSA 51,is led through the dielectric post 52 a and on the outer side of abattery 45. The linear radiating element 52 b are formed along theperiphery of the dielectric post 52 a, and their upper ends areconnected DC-wise or capacitively to the conductor 53 for power supply.

In the MSA antenna 51, the desired frequency for circular polarizationoperation can be obtained by controlling the diameter and length of thecylindrical member, the dielectric constant and thickness of thedielectric base 51 c and so forth. The frequency varies by several toseveral ten MHz depending on the width and size of the helical antennas52, and it is necessary to preliminarily take the variations intoconsiderations.

By making the helical antenna 52 and the MSA 51 to be identical in shape(i.e., sectional profile and size) as in this embodiment, substantiallyuniform directivity can be obtained substantially in all the directionsto the apex from low elevation angles.

A plurality of single-phase dry cells 45 can be provided in series asbattery power supply in the inside of the composite antenna by removingthe MSA 51 (inclusive of the disc conductor 53), then the removed MSA 51(inclusive of the disc conductor 53) can be mounted on the open antennatop, and a cap 55 can be fitted. When the MSA 51 is mounted, the powersupply line 51 d led along the inner wall surface of the compositeantenna 5 is connected to the power supply pin 51 a.

FIGS. 13(A) to 13(C) show a further embodiment of the invention, is asingle mode mobile satellite communication unit constituted by the solebase unit A for iridium plan communication system without being combinedwith the portable unit B for terrestrial communication system.

The base unit A has a cylindrical space 5A capable of accommodating alarge size battery 45, and a cylindrical frame 5 of the cylindricalspace 5A serves as an antenna. This base unit A has a wedge-liketriangular transversal sectional profile so that it can be readilygripped. This is suitable from the standpoint of the human engineering.

The base unit A has a vertically elongate, substantially rectangularshape, and its front face has a speech transducer section and variousother circuits. The front face also has a receiver loudspeaker 33A and adisplay section 14A provided therebelow for displaying variousinformation, such as data transmitted by key operation or the like.

The front face further has function keys 17A for volume control,function selection and various other functions and ten keys 16A providedin a lower portion. A power switch, a call switch and service keys 15provided in a further lower portion and constituted by on-hook switchesare provided on a further lower portion. Designated at 34A ia amicrophone. For the remainder of the construction, the antenna 5 and thetransverse sectional profile of the frame of this base unit are the sameas those in the previous embodiments.

FIG. 8 is a block diagram showing the internal circuit construction ofthe base unit A for the iridium plan communication system and theportable unit B used in the previous embodiments shown in FIGS. 1 to 7,particularly the embodiment shown in FIGS. 5(A) to 5(C), 6(A) and 6(B).

Referring to the figure, provided on the side of the portable unit B area microphone 34, a loudspeaker 33, a key section/controller 35(including a phone book memory), a display section 14, a cordiac 37 forconverting analog speech signal to PCM data and vice versa, and an MMI(man-machine interface) 38 performing such user's interface processes askey control and display section control.

An iridium plan communication unit function circuit, which is necessaryfor transmitting and receiving PCM data from the cordiac 37 via aniridium plan communication system line, is provided on the side of thebase unit A. A terrestrial communication unit function circuit, which isnecessary for transmitting and receiving PCM data from the cordiac 37 toand from base stations, is provided on the side of the portable unit B.

A bocoder 39, a link layer 40, a channel cordiac 41, a radio section 42and a modulator/demodulator 43 are provided on each of the two units.The bocoder 39 compresses and expands the PCM data. The linkk layer 40is a radio controller for radio communication, and is divided intolayers in dependence on the role of control. The channel cordiac 41converts data from the link layer 40 or the bocoder 39 to a flame formatof an iridium plan or terrestrial communication line by adding apreamble, unique words, error correction, a detection code, etc. Theradio section 42 has a function of setting a radio channel of theiridium plan or terrestrial communication line and performs frequencyconversion to a predetermined radio frequency. The modulator/demodulator43 demodulates analog signal from the radio section 42 to digital dataand extracts desired wave data via a band-limiting filter and an AGC,and also modulates digital data from the channel cordiac 41 and limitsthe modulated data to a minimum necessary band via a band-limitingfilter. As batteries 44 and 45, dry cells, lithium ion cells,nickel-hydrogen cells and so forth are used and accommodated in therespective units.

The functions of the above circuit construction will now be described inconnection with the embodiment shown in FIGS. 5(A) to 5(C), 6(A) and6(B). By mounting the portable unit B in the base unit A, the switches11F are automatically turned on. Then by turning on the power switch 2,the infrared transducers 3 and 12 of the units A and B are brought to aface-to-face relation and electrically coupled together. The LEDs 17Fand 21 of the portable and base units B and A are thus turned on tonotify that the iridium plan communication system line has beenconnected.

To make a call in this state, a call signal is transmitted from the sideof the portable unit B by utilizing the call switch or the ten keys 16provided therebelow. The call signal is coupled via the MMI 38 to theinfrared transducer 12 in the portable unit B. The infrared transducer12 converts the input call signal to infrared rays which are transmittedto the infrared transducer 3 on the side of the base unit A. Theinfrared transducer 3 demodulates the received infrared rays to theoriginal signal. This signal is sent out via the radio section 42.

After the call transmission, the base unit receives the call-receiveresponse of the opposite side, and then the off-hook of the oppositeside unit is visually confirmed on the side of the portable unit B inthe converse signal flow to that described above. Then, a predeterminedservice is started.

Speech signal from the microphone on the side of the portable unit B isconverted in the cordiac 37 to PCM data, which is coupled via theinfrared transducers 12 and 3 to the bocoder 39 in the base unit A. ThePCM data thus can be sent out via the channel cordiac 41 and the radiounit 42 to the iridium plan communication system line.

The receive-call and receiving operations are performed in the samemanners as above via the infrared transducers 12 and 3.

Where the highly directive infrared transducers 12 and 3 are used as inthe above embodiment, these infrared transducers 12 and 3 should be heldin direct face-to-face relation to each other for electric coupling.Suitably, the electric coupling can be obtained with low directivity andin a narrow transmission distance range of 1 to 5 m. In such a case, theelectric coupling can be obtained by carrying the base and portableunits A and B separately, for instance by putting the portable unit B ina suit pocket and putting the base unit A in a briefcase.

FIG. 9 shows a block diagram such an embodiment. In this embodiment,planar antennas 25 and 26 for transmitting and receiving weakelectromagnetic waves, are provided on the units A and B. The planarantennas 25 and 26 may be provided in any locality on the units A and B.In addition, r-f modulator/demodulators 22 and 23 for modulating theabove PCM data or the like to the carrier waves and also demodulatingthe received carrier waves to PCM data or the like, are provided on theunits A and B at predetermined positions thereof. Weak electromangeticwaves (hereinafter referred to as carrier waves) obtained as a result ofmodulation in the r-f modulator/demodulators 22 and 23, can betransmitted and received between the planar antennas 25 and 26 with lowdirectivity and in a narrow range of 1 to 5 m.

With the above construction, the functions noted above can be attainedby modulating the PCM data or the like to carrier waves in the units Aand B and transmitting the carrier waves via the planar antennas 25 and26 and also demodulating the received carrier waves in the r-fmodulator/demodulators of the other units B and A.

Particularly, unlike the previous embodiments, the carrier waves can bereceived via the planar antennas 25 and 26 of the units A and B evenwhen the portable unit B is not mounted in the base unit A, for instancewhen the portable unit B is put in a suit pocket while putting the baseunit A in a briefcase. When the user is in a region in which the carrierwaves can be received, electric coupling controllers 27 and 28 providedon the units A and B detect this and, as a result, the key LED 17F ofthe portable unit B and the LED 21 of the base unit A are turned on,thus notifying that the iridium plan communication system line stand-bystate prevails.

The user, even having the base unit A put in a briefcase, can confirmthat the key LED 17F on the side of the portable unit B is “on”, andenter into iridium plan communication.

When the portable unit B alone is carried, the user may get out of theregion in which the carrier waves of the units A and B can be received.This is detected by the electric coupling controllers 27 and 28 of theunits A and B. As a result, the key LED 17F of the portable unit Part Band the LED 21 of the base unit A are turned off or or provide redlight, notifying that the iridium plan communication system line is nolonger connected. Also, the electric coupling controller 27 on the sideof the base unit A turns off the power switch 29, thus bringing about an“off” or non-stand-by state.

With the LED 17F of the portable unit B in the “off” state, the uservisually confirms that iridium plan communication cannot be made andthat it is possible to utilize the sole terrestrial communication line.

When the user carrying the portable unit B gets into the region in whichthe carrier waves can be received again, the electric couplingcontrollers 27 and 28 of the units A and B detect this. As a result, thepower switch 29 of the base unit A is turned on again, and the LEDs 17Fand 21 of the units B and A are turned on to notify that the iridiumplan communication system line prevails.

FIG. 10 shows a further embodiment, in which electro/optical transducers46 and 47 are provided for transmitting and receiving signal via anoptical fiber.

Effects of the Invention

As has been described in the foregoing, according to the presentinvention it is possible to selectively use two different unitfunctions, i.e., the mobile satellite communication unit function andthe terrestrial communication unit function. When using the soleterrestrial communication unit function, unlike the prior art dual modeunit, no large and heavy unit frame need be carried, and the user isfree from great weight burden.

According to the present invention, in addition to the provision of aunit which is suitable from the human engineering standpoint, it ispossible to provide a dual mode mobile satellite communication unitwhich utilizes, for keying operation and also transmission andreception, a key operating section and a speech transducer section of amobile terrestrial communication unit. Since it is possible toselectively use the mobile terrestrial communication unit for shortdistance communication and the mobile satellite communication unit forlong distance communication, logical communication cost reduction can beobtained. Besides, since the key operating section and the speechtransducer section are provided on the side of the mobile terrestrialcommunication unit alone, the weight burden of the mobile satellitecommunication unit can be correspondingly alleviated.

According to the present invention, for global communication such asiridium plan communication, a plurality of different terrestrialcommunication units for PHS or cellular system communication can beselectively used depending on areas where such units are sold and used.That is, it is readily possible to replace the terrestrial communicationunit with those prescribed in various countries or areas.

According to the present invention, the provision of the hollowcylindrical antenna, the inner cylindrical space of which is used as abattery insertion space, Permits dispensing with any independent batterymounting space. This permits very great space saving particularly in themobile satellite communication unit, which requires high power and largesize battery power supply.

By constructing the antenna as a composite antenna comprising amicrostrip planar antenna and a helical antenna in coaxial arrangement,it is possible to maintain line quality and also maintain communicationsensitivity in all directions around the apex irrespective of variationsof the position relation between satellite and antenna.

What is claimed is:
 1. A dual mobile satellite communication unitproviding a mobile terrestrial communication unit function in additionto a mobile satellite communication unit function, comprising: a baseunit not including at least a key operating section, a display sectionand a speech transducer section having a microphone and a loudspeakerand capable of providing the mobile satellite communication unitfunction; and a terrestrial communication portable unit including a keyoperating section, a display section and a speech transducer sectionhaving a microphone a loudspeaker and providing a pertinent mobileterrestrial communication unit function; wherein recesses andprojections are provided as mechanical couplers on the base unit and theportable unit for mechanically coupling the base unit and the portableunit to each other, and electric connectors are provided on the baseunit and the portable unit for electrically connecting the key operationsection, the display section and the speech transducer section havingthe microphone and the loudspeaker on the side of the terrestrialcommunication portable unit and a mobile satellite communication unitfunction section on the side of the base unit to one another when thebase unit and the portable unit are mechanically coupled to one another.2. The dual mode mobile satellite communication unit according to claim1, wherein a single electric connector is provided for making theelectric connection, and plural mechanical couplers capable of beingheld spaced apart by different distances are provided for the mechanicalcoupling of the base unit and the portable unit.
 3. The dual mode mobilesatellite communication unit according to claim 1, wherein a rail-likemechanical coupler movable in a predetermined axial direction isprovided for the mechanical coupling, and an electric connector for theelectric connection is disposed at the end of movement in the axialdirection of the mechanical coupler and in a fixed plane containing thepath of movement axis of the mechanical coupler.
 4. A mobile satellitecommunication base unit not including at least a key operating section,a display section and a speech transducer section having a microphoneand a loudspeaker, capable of providing a mobile satellite communicationunit function and including a signal transceiver section fortransmitting and receiving converted waves of transmission and receptionsignals to and from a separate terrestrial communication portable unit,said base unit utilizing a key operating section and speech transducersection of the portable unit via the signal transceiver section duringmobile satellite communication.
 5. A dual mode satellite communicationunit comprising: a mobile satellite communication unit not including atleast a key operating section, a display section and a speech transducersection having a microphone and a loudspeaker, capable of providing themobile satellite communication unit function and including a firstconverted wave transceiver section for transmitting and receivingconverted waves of transmission and reception signals to and from asecond converted wave transceiver section of a separate terrestrialcommunication portable unit; the terrestrial communication portable unitincluding a key operating section, a display section and a speechtransducer section having a microphone and a loudspeaker, providing apertinent terrestrial communication unit function and including thesecond converted wave transceiver section for transmitting and receivingconverted waves of transmission and reception signals to and from thefirst transceiver section of the mobile satellite communication unit,wherein the terrestrial communication portable unit is used forterrestrial communication; and the mobile satellite communication unitcan be used as a base unit for transmission and reception via the firstand second converted wave transceiver sections by utilizing the keyoperating section and the speech transducer section having themicrophone and the loudspeaker of the portable unit during mobilesatellite communication.
 6. The dual mode mobile satellite communicationunit according to claim 5, wherein when the terrestrial communicationportable unit is carried alone, and moves beyond a range permittingtransmission between the first and second converted wave transceiversections, a stand-by state of the mobile satellite communication baseunit is turned off.
 7. A mobile satellite communication unit utilizingsatellites orbiting around the earth as network switching nodes or adual mode mobile satellite communication unit providing a mobileterrestrial communication unit function in addition to a mobilesatellite communication unit function, wherein the unit comprises anantenna section including a microstrip planar antenna formed at an end,the antenna section having a hollow cylindrical shape defining a batteryinsertion space underneath the microstrip antenna.
 8. The mobilesatellite communication unit according to claim 7, wherein the unit hasa vertically elongated frame having a large thickness portion formed onone side, the hollow cylindrical antenna being inserted in the largethickness portion.
 9. The mobile satellite communication unit accordingto claim 7, wherein the antenna section is capable of elongation andcontraction, tilting or rotation relative to the unit frame or securedto the unit frame.
 10. The mobile satellite communication unit accordingto claim 7, wherein the antenna section is a composite antenna includinga microstrip planar antenna and a helical antenna in coaxialarrangement.
 11. A mobile satellite communication unit utilizingsatellites orbiting around the earth as network switching nodes or adual mode mobile satellite communication unit providing a mobileterrestrial communication unit function in addition to a mobilesatellite communication unit function; wherein a frame of the unit hasan asymmetric transversal sectional profile with respect to a front facehaving a key operating section and a display section, such that a largethickness portion is formed on one side and a small thickness portion onthe other side behind the front face, a hollow cylindrical antenna beinginserted in the large thickness portion, and an inner cylindrical spaceof the antenna being a battery insertion space.
 12. A mobile satellitecommunication unit utilizing satellites orbiting around the earth asnetwork switching nodes or a dual mode mobile satellite communicationunit providing a mobile terrestrial communication unit function inaddition to a mobile satellite communication unit function, wherein theunit has a front mounting section for mounting a separate mobileterrestrial communication unit and a large thickness portion formed onone side behind the mounting section, a hollow cylindrical antenna beinginserted in the large thickness portion, an inner cylindrical space ofthe antenna being a battery insertion space.
 13. The mobile satellitecommunication unit according to claim 12, which does not include atleast a key operating section, a display section and a speech transducersection having a microphone and a loudspeaker and is capable of keyingoperation and transmission and reception by utilizing a key operatingsection and a speech transducer section of a mobile terrestrialcommunication unit which is detachably mounted in the mounting section.14. A mobile satellite communication base unit not including at least akey operating section, a display section and a speech transducer sectionhaving a microphone and a loudspeaker, capable of providing a mobilesatellite communication unit function, wherein a recess and a projectionare provided as mechanical couplers on the base unit for mechanicalcoupling, and electric connectors are provided on the base unit forelectrically connecting a key operation section, a display section and aspeech transducer section on a side of a separate terrestrialcommunication portable unit and a mobile satellite communication unitfunction section on the side of the base unit to one another when thebase unit and the terrestrial communication portable unit aremechanically coupled to one another.